1. Field of the Invention
This invention relates generally to shopping carts, and more particularly to a shopping cart having an improved method of loading and unloading the cart through the use of a movable shelf.
2. Description of Related art
The following art defines the present state of this field:
Nicholl et al., U.S. Pat. No. 2,812,187 describes a nestable shopping cart with a movable bottom. This invention provides an improvement to shopping carts which the basket component may be expanded for added capacity without interfering with the ability of the carts to be nested together when not in use.
Young, U.S. Pat. No. 2,958,536 describes a telescoping grocery cart having a moveable bottom. This invention provides a means for increasing the loading capacity of the conventional telescoping cart by the provision of means for moving one or more of the walls of the cart outwardly from the normal lines of the cart structure as the lading is placed therein.
Oliver, U.S. Pat. No. 3,787,063 describes a shopping cart having a container adapted to receive articles therein, and having also wheels enabling the cart to be propelled along the aisles of a supermarket or similar establishment. The cart includes wheel-equipped frame structure having a container supported thereby for selective angular displacements between a generally horizontal position of use and a generally vertical position in which a plurality of carts can be disposed in successive juxtaposition with frame and container portions of one cart nested within frame and container portions of an adjacent cart. The container has a movable bottom wall displaceable between retracted and extended positions in accordance with the magnitude of the weight supported at any time by the bottom wall, thereby making the chamber defined by the container automatically expandable to accommodate the size of the load placed therein by a shopper, and automatically retractable as such load is removed therefrom to facilitated unloading of the chamber at the check out counter of such market. The movable bottom wall is floatingly supported so that it will not bind if subjected to asymmetrical loading.
Close, U.S. Pat. No. 3,456,763 describes an invention related to a shopping cart and associated apparatus to assist unloading of said cart. The shopping cart includes a basket having a liftable tray covering the bottom thereof. The tray may be raised as the basket is being unloaded to lift goods in the basket to the level of the checkout stand and the top of the basket wall. Elevating means are connected to the tray for raising same to render the goods supported thereon accessible for unloading.
Ettlin, U.S. Pat. No. 5,265,893 describes a planar, rigid structure intended to provide a removable, horizontal division of the interior of a four wheeled wire frame grocery cart. A flat, rigid structure, dimensioned for the particular manufacture of cart, possesses a member for obtaining support from at least one of the several pairs of opposed longitudinal bars found in the standard wire frame cart construction. The member enables positioning of the shelf by abutment of one side of said shelf against one interior side of the cart while holding the opposed side of the shelf from a position above the level of abutment and then simply releasing.
Ruttenberg et al., U.S. Pat. No. 3,437,176 describes a grocery cart with an inclined bottom having a front opening gate system. This invention relates to an automatic cart unloading system utilizing a wheeled cart which has a substantially inclined bottom wall sloping downwardly toward the front of the cart and a frontwardly opening gate system. The shopping cart is designed to be used with a check stand having a substantially depressed zone therein and open at one end. A conveyor system is disposed in the depressed zone. The counter is further provided with means for holding a shopping cart against the open end of the check stand and with means for opening the gate on the shopping cart. Thus, when a cart is so held and its gate so opened the goods in the shopping cart will gravitationally slide out of the cart onto the conveyor system.
McConnaughhay, U.S. Pat. No. 3,513,944 describes a shopping cart unloading apparatus for facilitating ready unloading of grocery carts or merchandise shopping carts of self service stores. The apparatus includes means for elevatingly tilting or bodily lift-tilting a shopping cart so that its fore and aft axis is tilted downwardly. The apparatus includes a pivotally liftable carriage adapted to coactingly receive and lift a shopping cart. The carriage includes reach structure for pivotally moving a shopping cart in an upwardly sweeping arc thereby lift-tilting the basketed merchandise within easy reach of the checkout cashier.
Swanson, U.S. Pat. No. 3,924,709 describes an unloading assembly for shopping carts, which assembly moves the contents of the cart from the cart onto a stand, which stand may contain a scanner head for reading the prices on the individual items moved from the cart and across the top of the stand. Movement of the contents of the cart is accomplished by a belt which is positioned in the bottom of the basket of the cart and trained over a pair of spaced idler rollers, there being driving means carried by the stand whereby a pair of driven rollers of the driving means may be brought into engagement with the conveyor belt and one of the idler rollers and thus drive the belt and move the contents of the basket therefrom and onto the stand. An elevating mechanism may be provided on the stand to vertically shift the driving means and the cart to a position where the bottom of the cart basket is aligned with the top of a stand when the top of the stand is initially at a greater heights then the bottom of the basket.
Celms, U.S. Pat. No. 4,118,044 describes a gate construction for a shopping cart basket wherein a gate panel is disposed between sidewalls of the basket for closing an end thereof. The gate panel has its lower edge pivotally supported on a pair of brackets mounted to the sidewalls adjacent the lower comers thereof. A latch structure coacts between the sidewalls and the upper corners of the gate for holding the gate in a closed position.
Ulmer, U.S. Pat. No. 4,560,180 describes a shopping cart of the over-the-counter type that includes front gates that slide under the basket of the shopping cart for storage purposes. The gate bumpers that are constructed and defined to permit the slide-under action are interlocked with the front gate to prevent the ready theft of the front gate from the shopping cart. The front gate is provided with a positive latch to the basket to further prevent the unintentional opening of the gate. The baby seat compartment has a gate that may be pivoted forwardly and rearwardly as well as an upright back supporting position. The shopping cart is constructed of a single frame element for supporting the basket and baby compartment and functioning as a cart handle. The basket is pivotally supported on the frame element to permit it to be swung rearwardly to a storage position over the baby seat compartment. The forces transmitted to the baby seat compartment for elevating the basket are transmitted to the handle rather than the baby seat compartment.
The prior art teaches various apparatus for improving the loading and unloading of a shopping cart. However, the prior art does not teach a vertically movable shelf, mounted to move in accordance with shelf loading on a pair of spaced apart telescoping tracks, so as to make the unloading of items in the cart easier. The present invention fulfills these needs and provides further related advantages as described in the following summary.